I have an on going no start problem with a 2011GT/CS. When the key is turned to the start position, the dash lights come on but don't dim, there is no sound from the starter. The dealer has cleaned all the grounds, replaced the main wire harness and the shifter.Still no fix. Battery is OK. This is intermittent and usually the car starts eventually hours later.. It always starts for the dealer, so he has thrown up his hands and given up. I think that he thinks I am nuts. Veh has 115 K and has never been wrecked. Any suggestions?? All accessories work, lights, brake lights, e-brake light etc.

Ignition switch? Jiggle the key vigorously, and turn it very firmly (siamotainously) the next time this happens.

Honestly, I’ve done a lot of electrical work and no-start trouble-shooting. The car seems to have a good history from your description and no recent work to suspect. You should revisit possible grounding issues, these are sometimes hard to detect with causal checking.

Of course there could be non-ground connection problems, but I’d think old school if I were in your shoes. Start with the simple and work your way up, beginning with the ground connections.

I wonder if it could be an intermittent problem with the starter itself?
Has anyone mentioned maybe tossing another one in to see if that eliminates the problem?

Before replacing the starter you can run a lead from the starter to a test light. When you turn the ignition and the test light goes "on" but the starter doesn't crank, it's the starter. I had this issue with my GM 3800. It looked funny to have a wire routed through my window but it allowed me to identify that the cause of my no start was not the starter. (It was the BCM) But on every intermittent no start, my test light never lit.

Hi,
I also have a 2011 GT/CS it's a convertible. I also own an F150. I have had on occasion inserted the key into the ignition and it wouldn't start until I separated the f150 key from my key chain. Do you own other Fords that use the PATS system? The transponder inside the other keys can interfere with your security and cause the PATS system to recognize the wrong key,,, Just a thought. I noticed it when I use an all metal key chain BTW,,

In my experience, the lights would dim if the starter was getting current and just not turning the car over, or if the battery was bad. It sounds like the starter is not getting any current to it so I would check the ignition switch and the neutral switch on your automatic transmission; perhaps try jiggling the shift lever when it does not start. Of course on these new cars it could always be a computer problem. How about taking a video with your I-phone while you try to start the car, when it doesn't start you can at least show that to the dealer.

In my experience, the lights would dim if the starter was getting current and just not turning the car over, or if the battery was bad. It sounds like the starter is not getting any current to it so I would check the ignition switch and the neutral switch on your automatic transmission; perhaps try jiggling the shift lever when it does not start. Of course on these new cars it could always be a computer problem. How about taking a video with your I-phone while you try to start the car, when it doesn't start you can at least show that to the dealer.

The lights won't dim, no starter activity at all if the key isn't registered with the PATS system. If you cut a new key for this car but don't program the transponder in it the starter will NOT engage. Hope this helps

Thanks, RBK. I did take a video and the service Mgr. finally believes me. Again, this is a very intermittent problem. The last time the dealer had the car for 10 days and it always started for them. I counted 23 starts in a row after I got it back before it crapped out again. Called AAA and had it flat bedded back to the dealer, rolled it off and it promptly ef'ing started!!! Neutral switch?. I assume the dealer would have checked this first, but you never know. Maybe a dead spot in the starter, my next move would be to replace it a wait for it not to start again!! This car is a retired daily driver and is used mainly for road trips. Now, I can't trust it.

These intermittent problems can be frustrating, and I hate to recommend throwing parts at it as a diagnostic tool.
Top-notch had a very good suggestion for using a test light to see if his problem was being caused by the starter, or a failing Body Control Module (BCM). I believe that Ford refers to the "BCM" as a Constant Control Relay Module (CCRM).

Problem is, it always starts for the dealer. They have had the car now for two weeks and it starts three or four times a day! When it finally doesn’t start, then he will be able to use a draw test on the starter. Thanks.

My F 150 did the same thing , to get it going I lowered the steering column, it would start. Turned out to be an issue with the PATS system, was a loose wire around the ignition switch. If it happens again note your theft light if its blinking fast, that could be the issue. I also replaced my transceiver as well. All good now, hope you get that sorted